Are McDonald's fries even made of potatoes? Why are there 17 ingredients in its fries?

The fast-food giant lifted the veil on its fry production line and ingredient list Tuesday to dispel myths about one of its most popular items in two new videos.

The fry tour is the latest in a series of segments with former MythBusters star Grant Imahara aimed at addressing rumors about the quality of its food and improving transparency as it struggles to turn around its U.S. business.

Turns out, there are real spuds in the fries. As for that 17 number, that's a myth.

There are really 19 ingredients.

In addition to different oils, the list includes several chemicals that perform various functions, including ones that adds flavor, an anti-foaming agent that keeps oil from splattering, another aimed at keeping "the potatoes from going gray" and preservatives, Imahara explains.

"This is the ingredient dip, where we control the color, and we're adding dextrose – all natural sugar – to make sure that we get a consistent color no matter what time of the year it is," said Neher, adding that it also puts in sodium acid pyrophosphate to control "graying after freezing."